Venus is the only planet in our solar system that spins backward.

Venus takes 243 Earth days to complete just one spin on its axis. However, it only takes about 225 Earth days to zoom all the way around the Sun. This means you would celebrate a New Year on Venus more often than you would see a single sunrise! This strange backward movement is called retrograde rotation.Most planets spin the same way because they all started from the same swirling cloud of dust and gas. Astronomers believe Venus was once spinning normally until a massive object the size of a planet smashed into it billions of years ago. This crash was so powerful it might have knocked Venus completely upside down. Now, the Sun rises in the west and sets in the east on Venus.Another cool idea involves the planet's air. Venus has an incredibly thick atmosphere that is 90 times heavier than Earth's. Some researchers think the friction from these heavy clouds dragging across the surface slowed the planet down over millions of years. This thick air also traps heat like a giant blanket. Even though Mercury is closer to the Sun, Venus is the hottest planet with temperatures reaching 864 degrees Fahrenheit (462 degrees Celsius).